As the laser light source (for example, laser diode (LD)) has the characteristics of good monochromaticity, strong directivity and high luminance, the more attention is paid to the LD illuminating device and the LD illuminating device is used in various environments (e.g. medical devices, automobile headlamps, night vision monitoring, stage illumination and the like). Compared with a light-emitting diode (LED) illuminating device, the LD illuminating device has a longer illumination distance and a longer service lifetime.
In the related art, such LD illuminating device usually includes a laser diode array configured to generate laser beams; collimating lenses respectively corresponding to the laser diodes of the laser diode array and configured to collimate laser beams emitted from corresponding laser diodes; compression optics configured to reduce intervals between parallel laser beams emitted from respective collimating lenses; and a focus lens configured to converge light emitted from the compression optics. Ideally, the collimating lenses can collimate the laser beams into parallel light, and then the parallel light is focused on a desired location after compressed and converged, as shown in FIG. 1. However, practically as shown in FIG. 2, due to tolerance in practical manufacturing and decentering and tiling in assembling of the collimating lenses, light emitted from the collimating lenses is not parallel, thereby a light spot emitted from the focus lens will have the following problems, for instance, the light spot is expanded and deviated from a desired location (as shown by an arrow in FIG. 2), and thus, the light efficiency of the LD illuminating device is caused to be reduced.